This invention relates to a method, a device, a computer readable medium, a computer program element for top-of-form calibration of a printer, as well as a printer with the device.
Inkjet printer technology is increasingly making in-roads to the office and workgroup environment.
One problem that arises with a currently available printer is that due to mechanical tolerances and irregularity in paper stack up, there is a varying top-of-form position (xe2x80x9cprinting positionxe2x80x9d), which is the position of a medium when the top edge of the medium is directly under the last nozzle of the printer""s print head. This is the zero vertical axis (y-axis) position to which in the following all print positions make reference.
The word xe2x80x9cprint mediumxe2x80x9d is herein used as a representative of any medium such as paper or transparency upon which, for example, ink or toner may be printed by a printer.
A printer may as well be a printer using inkjet technology, laserjet(copyright) technology or any other printing technology for which it is important to have a calibration of a top-of-form position of the respective medium.
As yet there is no cheap and easy technology known which gives a sufficiently good automatic top-of-form calibration for a printer.
It is thus an object of the present invention to provide an easy, cheap and robust way for automatic top-of-form calibration of a printer.
The object is achieved by a method, a device, a computer readable medium and a computer program element for top-of-form calibration of a printer, as well as a printer with the device.
In the inventive method for top-of-form calibration of a printer, a printing medium is fed into a printing position. A predefined pattern is printed, thereby generating a print on the print medium. Subsequently, the print is detected from the print medium. After the print has been detected, a feature of the print being indicative of said printing position, such as the colour and/or the positional value of the print is determined from the detected print in dependency on a distinct positional characteristic of the print medium. Based on the determined feature of the print, a correction factor for correcting said printing position is determined. If for example, the positional value of the print is utilized as said feature of the print, it is compared with a predetermined reference positional value and, if present, a deviation of the determined positional value from the reference positional value is determined. The correction factor is then determined from said deviation. Eventually, the top-of-form calibration of the printer is processed by adjusting said printing position on the basis of the determined correction factor.
According to another aspect of the invention, a device for top-of-form calibration of a printer comprises means for performing the steps described above.
According to further aspects of the invention, a computer readable medium with a program recorded thereon and a computer program are provided, where the program makes the computer execute a procedure comprising the steps mentioned above.
The invention provides an easy, cheap and robust way for automatic top-of-form calibration of a printer.
Thereby the variability of the top-of-form position of the media in a printer can be reduced.
In this context, the predefined pattern is generated, for example, by a print head of an inkjet et printer.
Furthermore, the word xe2x80x9cprintxe2x80x9d is used for what is actually printed on the print medium after the predefined pattern has been generated.
The predefined pattern can comprise components of any form, for example, circles, rectangles, etc. and any combination thereof. In case of a colour printer the pattern may comprise components of different colours. It only has to be possible to determine a feature of the print such like the form, colour and/or the positional value of the print at a distinct position of the print medium. And said feature is indicative of the printing position, into which the medium has originally been fed. Once this feature of the print is determined, the calibration of this original printing position, i.e., the top-of-form position, can be carried out.
The invention may be implemented in a programmable computer device as well as with a special electronic circuit.